Camera flash photography systems

Camera system capable of flash photography comprising:

• means for producing a preliminary flash prior to the production of a primary flash to be used in actual photographing;
• a diaphragm aperture changeable from an initial aperture size;
• means for receiving light from said preliminary flash to generate a first signal;
• means for presetting an aperture value;
• and
• means, responsive to said first signal from said light receiving means and to said aperture value of said presetting means, for interrupting the change in aperture size of said diaphragm aperture, in accordance with said preset aperture value if a first relationship exists between said preset aperture value and said first signal, and in accordance with said first signal if a second relationship exists between said preset aperture value and said first signal,
• whereby said primary flash light is produced after the change in aperture size is interrupted.

Camera system capable of flash photography comprising:

• means for producing a preliminary flash prior to the production of a primary flash to be used in actual photographing;
• a diaphragm aperture changeable from an initial aperture size;
• means for receiving light from said preliminary flash to generate a first signal;
• means for presetting an aperture value;
• means, responsive to said first signal from said light receiving means and to said aperture value of said presetting means, for interrupting the change in aperture size of said diaphragm aperture, in accordance with said preset aperture value if a first relationship exists between said preset aperture value and said first signal, and in accordance with said first signal if a second relationship exists between said preset aperture value and said first signal,
• whereby said primary flash light is produced after the change in aperture size is interrupted;
• first means responsive to said preset aperture value for providing a first information indicative of a difference between the initial aperture size and an aperture size corresponding to said preset aperture value;
• second means responsive to said first signal for providing a second information indicative of a difference between the initial aperture size and an aperture size suitable for achieving an optimum exposure under a predetermined amount of said primary flash;
• and third means responsive to the change in the aperture size for providing a third information indicative of a difference between the initial aperture size and an actual aperture size realized by the change in aperture size;
• and wherein said interrupting means interrupts said change in aperture size when said third information coincides with said first and second information, and interrupts said change in aperture size when said third information coincides with said second information if a second relationship exists between said first and second information.

In a camera system capable of ordinary photography with the ambient light in a first mode and flash photography in a second mode in which a preliminary flash of a relatively long duration at a substantially constant intensity is produced prior to the production of a primary flash to be used in actual photographing, a camera in said camera system comprising:

• means for changing between said first and second modes;
• a diaphragm aperture having a changeable aperture size from an initial aperture size;
• means for receiving light through said diaphragm aperture during the change in aperture size from said initial aperture size, said receiving means generating a signal responsive to the intensity of the received light;
• means for generating a reference signal;
• means for comparing the signal of said receiving means and said reference signal during the change in said aperture size;
• means responsive to said comparing means for interrupting the change in said aperture size when a predetermined relation exists between the signal of said receiving means and said reference signal to determine the aperture size;
• means for causing said preliminary flash in synchronization with said change in the aperture size from said initial aperture size in said second mode;
• and
• means for shifting said reference signal in response to said changing means to accommodate said reference signal for the comparisons with the ambient light in said first mode and with the preliminary flash in said second mode.

Camera system capable of flash photography comprising:

• means for producing a preliminary flash prior to the production of a primary flash to be used in actual photographing;
• a diaphragm aperture changeable from an initial aperture size;
• means for receiving light from said preliminary flash to generate a first signal;
• means for presetting an aperture value;
• and
• means responsive to said first signal from said light receiving means and to said aperture value of said presetting means for determining the aperture size of said diaphragm aperture in accordance with a greater one of a pair of aperture sizes corresponding to said preset aperture value and to said first signal, respectively,
• whereby said primary flash light is produced after the aperture size is determined.